No coil light, no crank

[Harryca]

Hi all,

Occasionally when trying to start my mk7 2.4 tdci the coil light doesn’t come on when I turn the ignition on. When it doesn’t come on the van doesn’t crank. If I turn the key 5 or 6 times between the off position and the ignition position the coil light eventually comes on and the van will crank and start. There are no codes showing associated with this.
Any suggestions what I could start looking for?

Cheers,
Harry.

[knobby1]

Hi all,

Occasionally when trying to start my mk7 2.4 tdci the coil light doesn’t come on when I turn the ignition on. When it doesn’t come on the van doesn’t crank. If I turn the key 5 or 6 times between the off position and the ignition position the coil light eventually comes on and the van will crank and start. There are no codes showing associated with this.
Any suggestions what I could start looking for?

Cheers,
Harry.

Sounds like your ignition switch is not well...quite a common issue with the Mk6/7 Transits.

Cheap and easy to replace to rule it out.

Lord Knobrot

[Harryca]

Hi all,

Occasionally when trying to start my mk7 2.4 tdci the coil light doesn’t come on when I turn the ignition on. When it doesn’t come on the van doesn’t crank. If I turn the key 5 or 6 times between the off position and the ignition position the coil light eventually comes on and the van will crank and start. There are no codes showing associated with this.
Any suggestions what I could start looking for?

Cheers,
Harry.

Sounds like your ignition switch is not well...quite a common issue with the Mk6/7 Transits.

Cheap and easy to replace to rule it out.

Lord Knobrot

It’s a brand new switch. That was my first thought!

[knobby1]

Ah...you never mentioned you had replaced the ignition switch.

Possibly a poor earth, there's a multitude of earths on the transits, you need to check them all.

Lord Knobrot

[Jim Archer]

Was it doing this before the new switch? Assume you mean the contactor unit rather than lock body?

Jim

[Harryca]

Was it doing this before the new switch? Assume you mean the contactor unit rather than lock body?

Jim

I can’t say it was. The unit (not the lock) was replaced by a mechanic at the same time as the scv to try and fix an issue with it cutting out (which is still causing me a nightmare but that’s another issue). I have another brand new one in a box that I might try and fit but I can’t see it making any difference considering there’s already a new one on there.

Cheers,
Harry.

[knobby1]

Was it doing this before the new switch? Assume you mean the contactor unit rather than lock body?

Jim

I can’t say it was. The unit (not the lock) was replaced by a mechanic at the same time as the scv to try and fix an issue with it cutting out (which is still causing me a nightmare but that’s another issue). I have another brand new one in a box that I might try and fit but I can’t see it making any difference considering there’s already a new one on there.

Cheers,
Harry.

When the SCV was replaced...were the learns done..??

Lord Knobrot

[Harryca]

When the SCV was replaced...were the learns done..??

Lord Knobrot

A fuel pump learn was done, but I’ve since done the injector pilot and fuel pump learns again (Prv counter reset wouldn’t work in forscan) and the cutting out is now worse and I have an error code telling me to do a fuel pump learn. I’m thinking I’m just going to have to replace the PRV and SCV and do the learns again from scratch to rule out any issues. I’m getting a massive sudden spike in the actual fuel pressure which is followed by the van cutting out immediately.

Cheers,
Harry.

[knobby1]

When the SCV was replaced...were the learns done..??

Lord Knobrot

A fuel pump learn was done, but I’ve since done the injector pilot and fuel pump learns again (Prv counter reset wouldn’t work in forscan) and the cutting out is now worse and I have an error code telling me to do a fuel pump learn. I’m thinking I’m just going to have to replace the PRV and SCV and do the learns again from scratch to rule out any issues. I’m getting a massive sudden spike in the actual fuel pressure which is followed by the van cutting out immediately.Cheers,Harry.

Were the SCV & PRV genuine Ford/Denso items..?? If not genuine, we've found they either cause the engine to fail to start after fitting, struggle to pass the learns or fail soon after.

Lord Knobrot

[Harryca]

Were the SCV & PRV genuine Ford/Denso items..?? If not genuine, we've found they either cause the engine to fail to start after fitting, struggle to pass the learns or fail soon after.

Lord Knobrot

SCV was a denso item, PRV was tested and worked so wasn’t replaced. Fuel pump learn was completed so it clearly wasn’t causing too many issues and the SCV must have been working. For the cutting out issue I’m wondering whether to replace both Prv and scv with new genuine ones or just replace the Prv, and obviously do the learns again. I’m still scratching my head as to how I didn’t have any fault codes relating to this issue, I re-did the learns just to see if it made any improvement, they both completed first time without issue, and now I have a code telling me to do a fuel pump learn. What is that about?

Still no closer to figuring out the coil light no start issue either.

Cheers,
Harry.

[knobby1]

Were the SCV & PRV genuine Ford/Denso items..?? If not genuine, we've found they either cause the engine to fail to start after fitting, struggle to pass the learns or fail soon after.

Lord Knobrot

SCV was a denso item, PRV was tested and worked so wasn’t replaced. Fuel pump learn was completed so it clearly wasn’t causing too many issues and the SCV must have been working. For the cutting out issue I’m wondering whether to replace both Prv and scv with new genuine ones or just replace the Prv, and obviously do the learns again. I’m still scratching my head as to how I didn’t have any fault codes relating to this issue, I re-did the learns just to see if it made any improvement, they both completed first time without issue, and now I have a code telling me to do a fuel pump learn. What is that about?

Still no closer to figuring out the coil light no start issue either.

Cheers,
Harry.

How was the PRV tested..?? They're just a simple relief valve...but will hold silly amount of pressure, at least 1600 bar or 23,206psi, they either work or they don't. A simple check is to pop the PRV return line off and see if there's any fuel flow @ idle, it can be wet but no dripping or flow...or pull it out of the fuel rail and see if it's in pieces. If the PRV is blown, the engine will never start.

Cutting out at traffic lights or junctions and/or hunting idle out is usually the SCV causing it, the piston often sticks in the bore causing hysteresis and hence a hunting idle or cutting out due to too low a fuel flow.

Lord Knobrot

[Harryca]

How was the PRV tested..?? They're just a simple relief valve...but will hold silly amount of pressure, at least 1600 bar or 23,206psi, they either work or they don't. A simple check is to pop the PRV return line off and see if there's any fuel flow @ idle, it can be wet but no dripping or flow...or pull it out of the fuel rail and see if it's in pieces. If the PRV is blown, the engine will never start.

Cutting out at traffic lights or junctions and/or hunting idle out is usually the SCV causing it, the piston often sticks in the bore causing hysteresis and hence a hunting idle or cutting out due to too low a fuel flow.

Lord Knobrot

Disconnected from the plastic connector and van cranked, no fuel came out. It hasnt been taken out to see if it’s in pieces but the van starts fine. I did have hunting at idle but that stopped after the SCV was changed, but it still cuts out. It used to cut out and the revs would drop off instantly out but just about hang in there, all the dash lights would come on and after about 2-3 seconds you could drive it normally again without having to turn the key, but now it properly cuts out - the engine actually stops. I lose power steering and it’s caught me in some real tricky situations a couple of times, almost crashing into road barriers doing 50mph with no steering and having to pump the break pedal. Can’t drive the van anymore like that so need to get it sorted. But if it’s already had a brand new DENSO SCV at a cost of over £200 for the part alone, is another new one going to sort it?

Cheers,
Harry.

[Harryca]

Finally, after a long time I’ve finally found the issue. I hope I’m not speaking too soon, but so I seem to have resolved the starting issue, as well as the cutting out issue I was having (different post - will also update that).

I found a very slightly corroded pin on a relay, and it didn’t seem to be making good contact. Specifically the glow plug relay at the very top of the engine bay fuse box. With the engine running, I could wiggle it and the engine would cut out. If I pulled the relay out, the coil light wouldn’t come on when turning the ignition on, and there would be no crank. Cleaned this up and bent the leg slightly so it made better contact. So far so good, coil light comes on every time, van starts as normal, hasn’t cut out once.

[knobby1]

Finally, after a long time I’ve finally found the issue. I hope I’m not speaking too soon, but so I seem to have resolved the starting issue, as well as the cutting out issue I was having (different post - will also update that).

I found a very slightly corroded pin on a relay, and it didn’t seem to be making good contact. Specifically the glow plug relay at the very top of the engine bay fuse box. With the engine running, I could wiggle it and the engine would cut out. If I pulled the relay out, the coil light wouldn’t come on when turning the ignition on, and there would be no crank. Cleaned this up and bent the leg slightly so it made better contact. So far so good, coil light comes on every time, van starts as normal, hasn’t cut out once.

Strange...they don't need glow plugs to start...I pulled my glow plug relay out years ago and have had no issues starting. Also a Mk7 2.4.

Lord Knobrot